Up to now, in a mobile communication system for mobile phones and the like, transmission power control is performed on wireless communication between a base station and a mobile communication terminal. In general, this transmission power control is performed such that the reception level of the base station, the ratio of the reception level to noise, or the ratio of the reception level to the sum of noise and interference is constant. The mobile communication terminal transmits data with a relatively small transmission power when being located near the base station, and transmits data with a relatively large transmission power when being located far from the base station. Such a mechanism can maintain the channel quality of the wireless communication, and also can achieve lengthened battery duration of the mobile communication terminal.
Patent literature 1 describes a method for minimizing a decrease in channel quality while further reducing consumed power. The average transmission power in a set control period is made equal to or less than a given value, whereby an increase in transmission power is prevented when the channel quality is poor.